It’s time for Trump to attack Iran’s Revolutionary Guard.

When Iran flew an unmanned aerial vehicle into Israel this weekend, the mullahs were testing President Trump, not just Israel. The Iranian drone, reportedly based on US technology, was a reminder of America’s abandonment of an active military deterrent, which began in 2011 when President Barack Obama allowed Iran to recover a highly classified UAV...

Time: 22:00&nbsp&nbsp&nbsp&nbsp Date: 12.02.2018

In the years that followed, Obama applied intense pressure to prevent an Israeli airstrike on Iranian nuclear facilities, abandoned coercive diplomacy to appease Tehran in nuclear negotiations and responded to the capture of 10 US sailors with the diplomatic equivalent of “Thank you, sir, may I have another.”

Worse still was Obama’s refusal to act in Syria, even to enforce his own red line on the use of chemical weapons. The Obama administration said the Syrian air-defense system made a no-fly zone too dangerous to enforce. Yet hundreds of thousands of dead Syrians later, the Israeli Air Force wiped out half of Syria’s air defenses on Saturday afternoon.

Iran’s leaders observed and internalized American weakness. In response, they intensified their pursuit of a regional hegemony with the money and diplomatic cover from the flawed nuclear deal to spread terror and missiles throughout the Middle East.

And while President Trump entered office wielding aggressive rhetoric toward Iran and vowing to tear up the nuke deal, Tehran still doesn’t know what to make of him.

On one hand, Trump’s decision to impose sanctions on Iran’s Revolutionary Guard Corps along with his uncompromising indictment of the nature of the Iranian regime at the United Nations showed a willingness to engage in ideological and economic warfare. On the other, the nuclear deal remains in place, and his administration has done little to raise the cost to Iran for its regional expansion.

Iran still smuggles weapons into Bahrain, the home of the US Navy’s Central Command and missiles into Yemen to launch attacks against Saudi Arabia, while building missile-production facilities in Syria and Lebanon.

Now is the time for Trump to re-establish a robust military deterrent toward Iranian expansionism in close collaboration with regional allies.

His administration declared the Revolutionary Guard a terrorist entity in October, and he should target key Guards’ bases and weapons in Syria accordingly. Such an approach could help prevent a larger-scale conflict.

Iran’s leaders tend to avoid direct military confrontation against a superior military power. Saudi officials like to tell the story of the 1984 shoot-down of two Iranian fighters that crossed into Saudi airspace. When the line was next tested in 1988, the Iranians turned back before being intercepted and never tested Saudi Arabia again.

Furthermore, the mullahs know that if they direct more money into extraterritorial operations, their economic and political situation at home will deteriorate. The Iranian people are already chanting, “Let go of Syria, think about us.” Raising the cost for Iran in Syria would exacerbate internal tensions.

First, Tehran’s strategic calculus would start to change, curtailing risk-taking in the region, enhancing security for US allies over the long run and potentially changing regime behavior in other illicit activities.

Second, a US military deterrent would close the so-called “land bridge” that gives Iran an uninterrupted line of influence to the Mediterranean. And that deterrent would undergird Trump’s threats to exit the nuclear deal, which could dramatically increase the likelihood that attempts to fix the deal succeed while significantly reducing the risks of an Iranian escalation should he decide to nix it.

Finally, the United States would reclaim diplomatic leverage over Russia in Syria. If Vladimir Putin wants to maintain a long-term presence and profit off the country’s reconstruction, he’ll have to clear Iranian forces out of Syria or America and its allies will do it for him.

But without that deterrent, America will keep sleepwalking into an era of Iranian hegemony in the Middle East. This weekend’s events should be a final wake-up call.

Richard Goldberg is a senior adviser at the Foundation for Defense of Democracies.
@rich_goldberg